Endometrial Thickness and Histopathological Findings in Females with Perimenopausal Abnormal Uterine Bleeding

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Abstract

Introduction: Abnormal uterine bleeding (AUB) is one of the most common gynecological complaints among perimenopausal females and often reflects a wide spectrum of underlying endometrial abnormalities ranging from benign hormonal changes to premalignant and malignant lesions. The present study was conducted to assess the association between endometrial thickness measured by Transvaginal Sonography (TVS) and histopathological findings in perimenopausal females presenting with abnormal uterine bleeding. Methods & Materials: This cross-sectional analytic observational study was conducted in the Department of Gynecology and Obstetrics of Mugda Medical College & Hospital, Dhaka, Bangladesh, from February 2025 to January 2026. A total of 100 consecutive perimenopausal females aged 40-55 years who attended the gynecology outpatient department with complaints of abnormal uterine bleeding were enrolled using purposive sampling. Data were collected using a structured case record form and entered into Statistical Package for the Social Sciences (SPSS) version 26.0 for analysis. Result: Heavy menstrual bleeding was the most common presentation (44.0%). The mean endometrial thickness was 11.9 ± 3.8 mm, with most females having an endometrial thickness of 11-15 mm (38.0%). Histopathologically, proliferative endometrium was the predominant finding (34.0%), while significant endometrial pathology, including hyperplasia and carcinoma, was identified in 26.0% of cases. A statistically significant association was observed between increasing endometrial thickness and the presence of hyperplasia and carcinoma (p = 0.002), and mean endometrial thickness increased progressively with the severity of histopathological abnormality (p <0.001). Conclusion: This study showed a significant association between endometrial thickness measured by transvaginal ultrasonography and the underlying histopathological abnormalities in perimenopausal females presenting with abnormal uterine bleeding. Clinically important endometrial lesions, including hyperplasia and carcinoma, were detected in 26.0% of the participants. A progressive increase in endometrial thickness was accompanied by a corresponding rise in the occurrence of hyperplasia and carcinoma, with the greatest risk identified in females whose endometrial thickness was greater than 15 mm. Assistant Professor, Department of Obstetrics and Gynaecology, Mugda Medical College & Hospital, Dhaka, Bangladesh farhanakabirdh@gmail.com (ORCID: 0009-0001-3567-5038) Medical Officer, Department of Obstetrics and Gynaecology, Mugda Medical College & Hospital, Dhaka, Bangladesh Assistant Professor, Department of Obstetrics and Gynaecology, Mugda Medical College & Hospital, Dhaka, Bangladesh Assistant Professor, Department of Obstetrics and Gynaecology, Mugda Medical College & Hospital, Dhaka, Bangladesh INTRODUCTION Perimenopausal abnormal uterine bleeding (AUB) is a common gynaecological problem and often reflects the hormonal instability of the menopausal transition, during which ovulation becomes irregular and endometrial shedding becomes unpredictable. AUB accounts for a substantial proportion of gynaecological consultations and significantly affects women's quality of life. Studies have shown that perimenopausal females constitute a considerable proportion of patients presenting with AUB, emphasizing the clinical importance of evaluating endometrial pathology in this age group [1]. The FIGO PALM-COEIN classification has improved the understanding and management of AUB by categorizing structural and non-structural causes of bleeding. Contemporary reviews and international recommendations continue to support transvaginal ultrasonography (TVS) as the first-line imaging modality for evaluating AUB, while endometrial sampling is recommended for females with persistent bleeding, risk factors for malignancy, or suspicious imaging findings [2,3]. However, interpretation of endometrial thickness (ET) in perimenopausal females is more challenging than in postmenopausal females because the endometrium still undergoes physiological cyclic variation [4]. Histopathological examination remains the gold standard for diagnosing endometrial disorders because ultrasound findings alone cannot reliably differentiate benign proliferative changes from hyperplasia, atypia, or carcinoma. Correlation between sonographic ET and histopathological findings is therefore essential for improving diagnostic accuracy [5]. In a study of females with AUB, perimenopausal patients represented a significant subgroup, and a wide spectrum of endometrial lesions was observed, ranging from normal cyclical endometrium to hyperplasia and malignancy [1]. Several recent studies have investigated the predictive value of ET for significant endometrial pathology. Thoprasert et al. demonstrated that an ET of 8 mm or more was significantly associated with abnormal endometrial histopathology in perimenopausal female with uterine bleeding [6]. Similarly, Sahu et al. reported that increased ET was more frequently associated with abnormal histological findings and concluded that ET can be a useful adjunct in the evaluation of AUB [7]. In a 2024 study, Selvam and Lakshminarayanan found that ET greater than 8 mm was strongly associated with premalignant and malignant lesions in perimenopausal females with heavy menstrual bleeding [8]. More recently, Moshey et al. suggested that endometrial sampling should be strongly considered when ET exceeds 11 mm in perimenopausal females, particularly when bleeding is persistent or recurrent [9]. Despite these findings, no universally accepted ET cut-off exists for perimenopausal AUB. Reported threshold values vary across studies because of differences in study design, patient characteristics, and histopathological criteria. Benign conditions such as proliferative endometrium, secretory endometrium, and polyps may also present with increased ET, creating overlap with premalignant lesions [4,8]. Therefore, ET should be interpreted in conjunction with clinical features and histopathological assessment rather than as an isolated parameter. The histopathological spectrum of perimenopausal AUB includes proliferative endometrium, secretory endometrium, disordered proliferative endometrium, endometrial polyps, hyperplasia without atypia, atypical hyperplasia, and carcinoma [1,5,7]. Identification of these lesions is particularly important in resource-limited settings, where unnecessary invasive procedures should be avoided while ensuring early detection of significant disease. International recommendations emphasize a balanced approach that combines clinical assessment, imaging, and selective endometrial sampling [3,10]. The present study aims to assess endometrial thickness measured by TVS and correlate it with histopathological findings in females presenting with perimenopausal abnormal uterine bleeding. METHODS & MATERIALS This cross-sectional analytic observational study was conducted in the Department of Gynecology and Obstetrics of Mugda Medical College & Hospital, Dhaka, Bangladesh, from February 2025 to January 2026. A total of 100 consecutive perimenopausal females aged 40-55 years who attended the gynecology outpatient department with complaints of abnormal uterine bleeding were enrolled using purposive sampling. Perimenopause was defined as the period of menstrual irregularity and hormonal transition preceding menopause. females with pregnancy-related bleeding, known coagulation disorders, cervical malignancy, previously diagnosed endometrial carcinoma, use of hormone replacement therapy, or those unwilling to participate were excluded from the study. After obtaining informed written consent, a detailed history was taken regarding age, marital status, parity, body mass index (BMI), menstrual pattern, and associated medical conditions such as hypertension and diabetes mellitus. A complete general and gynecological examination was performed for all participants. All enrolled females underwent transvaginal ultrasonography using a high-frequency endovaginal probe. Endometrial thickness was measured in the sagittal plane at the thickest part of the endometrium as the maximum double-layer thickness from one endomyometrial interface to the other. The measured values were recorded in millimeters and categorized as <8 mm, 8-10 mm, 11-15 mm, and >15 mm. Following ultrasonographic evaluation, endometrial sampling was performed in all participants by dilatation and curettage or endometrial biopsy according to clinical indication and departmental protocol. The obtained specimens were fixed in 10% formalin and sent to the pathology laboratory for histopathological examination. Histopathological diagnoses were classified as secretory endometrium, proliferative endometrium, disordered proliferative endometrium, endometrial polyp, hyperplasia without atypia, atypical hyperplasia, and endometrial carcinoma. Data were collected using a structured case record form and entered into Statistical Package for the Social Sciences (SPSS) version 26.0 for analysis. Categorical variables were expressed as frequency and percentage, while continuous variables were presented as mean ± standard deviation (SD). Differences in mean endometrial thickness among histopathological groups were analyzed using one-way analysis of variance (ANOVA). A p-value of <0.05 was considered statistically significant. Ethical approval for the study was obtained from the Institutional Ethics Committee of the hospital before commencement of data collection. RESULTS The majority of females were aged 45-49 years (47.0%), followed by 40-44 years (28.0%) and 50-55 years (25.0%) (Table I). Table I Age distribution of the study participants (n = 100). Age group (years) Frequency (n) Percentage (%) 40-44 28 28.0 45-49 47 47.0 50-55 25 25.0 Total 100 100.0 Most females were married (92.0%) and multiparous (72.0%). Obesity (BMI ≥30 kg/m²) was observed in 31.0% of the study population (Table II). Table II Marital, parity, and obesity status of the study participants (n = 100). Variables Frequency (n) Percentage (%) Marital status Married 92 92.0 Parity Multiparous (≥2) 72 72.0 Obesity status Obesity (BMI ≥30 kg/m²) 31 31.0 Heavy menstrual bleeding was the most common presenting complaint (44.0%), followed by irregular menstrual bleeding (29.0%). Hypertension and diabetes mellitus were present in 26.0% and 18.0% of females, respectively (Table III). Table III Clinical profile of females with perimenopausal AUB (n = 100). Clinical variables n (%) Bleeding related Heavy menstrual bleeding 44 (44.0) Irregular menstrual bleeding 29 (29.0) Frequent bleeding 14 (14.0) Intermenstrual bleeding 8 (8.0) Prolonged bleeding 5 (5.0) Others Hypertension 26 (26.0) Diabetes mellitus 18 (18.0) The mean endometrial thickness was 11.9 ± 3.8 mm. Most females had an ET of 11-15 mm (38.0%), while 17.0% had a markedly thickened endometrium of >15 mm (Table IV). Table IV Endometrial thickness on transvaginal ultrasonography (n = 100). Endometrial thickness (mm) n (%) <8 mm 18 (18.0) 8-10 mm 27 (27.0) 11-15 mm 38 (38.0) 15 mm 17 (17.0) Mean ET ± SD 11.9 ± 3.8 mm The commonest histopathological pattern was proliferative endometrium (34.0%). Significant endometrial pathology comprising hyperplasia without atypia (18.0%), atypical hyperplasia (5.0%), and endometrial carcinoma (3.0%) was identified in 26.0% of females (Table V). Table V Histopathological findings of endometrial sampling (n = 100). Histopathological diagnosis n (%) Proliferative endometrium 34 (34.0) Secretory endometrium 16 (16.0) Disordered proliferative endometrium 14 (14.0) Endometrial polyp 10 (10.0) Hyperplasia without atypia 18 (18.0) Atypical hyperplasia 5 (5.0) Endometrial carcinoma 3 (3.0) A statistically significant association was observed between increasing endometrial thickness and the presence of hyperplasia or carcinoma (p = 0.002). Significant pathology was found in only 5.6% of females with ET <8 mm, compared with 14.8% in the 8-10 mm group, 28.9% in the 11-15 mm group, and 58.8% among females with ET >15 mm, demonstrating a clear positive trend (Table VI). Table VI Association between endometrial thickness and histopathological findings (n = 100). Endometrial thickness Benign histology n (%) Hyperplasia/Carcinoma n (%) p-value <8 mm (n=18) 17 (94.4) 1 (5.6) 0.002 8-10 mm (n=27) 23 (85.2) 4 (14.8) 11-15 mm (n=38) 27 (71.1) 11 (28.9) 15 mm (n=17) 7 (41.2) 10 (58.8) Total 74 (74.0) 26 (26.0) - Mean endometrial thickness increased progressively with the severity of histopathological abnormality. Females with secretory endometrium had the lowest mean ET (8.9 ± 1.6 mm), while those with endometrial carcinoma had the highest mean ET (19.4 ± 2.1 mm). The difference in mean ET across histopathological categories was highly significant (p < 0.001), indicating a strong correlation between ultrasonographic endometrial thickness and underlying endometrial pathology (Table VII). Table VII Mean endometrial thickness in TVS according to histopathological diagnosis (n = 100). Histopathological diagnosis Mean ET ± SD (mm) p-value* Secretory endometrium 8.9 ± 1.6 <0.001 Proliferative endometrium 10.1 ± 2.0 Disordered proliferative endometrium 11.8 ± 2.3 Endometrial polyp 12.7 ± 2.6 Hyperplasia without atypia 14.6 ± 2.8 Atypical hyperplasia 16.9 ± 2.4 Endometrial carcinoma 19.4 ± 2.1